Balanced slide-valve



(No Model.)

E. L. MILLS.

BALANCBD SLIDE VALVE.

No. 485,818. Patented No'v. 8, 1892. 227,5, fljgl'z lllllllllllll In ylllllllllllllllllllllllli WILUEEEEE NEWER 726 Y A Ua/MM. ma@ 9%. gMZI/gw Ynsuomus vrsn so. momumo, wAsmNcToN n c UNITED STATES PATENT OFFICE.

EDWARD L. MILLS, OF ERIE, PENNSYLVANIA.

BALANCED SLIDE-VALVE.

SPECIFICATION forming part of Letters Patent No. 485,818, dated November 8, 1892.

Application filed July 21, 1892. Serial No. 440,833. (No model.)

To all whom it may concern.:

Be it known that I, EDWARD L. MILLS, a citizen of the United States, residing at the city of Erie, in the county ot' Erie and State of Penn- Sylvania, have invented certain new and useful Improvements in Balanced Slide-Valve Mechanism; and I do hereby declare the following to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, forming part of this specification.

My invention consists in the improvements in balanced slidevalve mechanism hereinafter set forth and explained, and illustrated in the accompanying drawings, in which- Figure l is a side elevation of a steam-engine cylinder, showing the valve-seat and the steam-ports therein. Fig. 2 is a longitudinal horizontal section of a steam-engine cylinder and the steam-chest thereon embodying my invention. Eig. 3 is a transverse section of the same on the line y y in Fig. l, looking in the direction of the arrow. Fig. 4 is atransverse section of the same on the line fr c: in Fig. l, looking in the direction of the arrow. Fig. 5 is a plan view of the under side of my improved relief-plate. Fig. 6 is an end View in elevation of the same. Fig. 7 is a side view in elevation of the same. Fig. 8 is a plan view of my improved Valve. Fig. 9 is an end view of the same.

Like letters refer to like parts in all of the figures.

In the construction of my improved balanced slide-valve mechanism shown in the drawings, A is a steam-engine cylinder, and B a steam-chest secured thereto in the usual manner. In the bottom of the steam-chest are two main steam-ports C C, a central exhaust-port D, and four auxiliary ports E E E E, these auxiliary ports opening into the steam-passages F F to the ends of cylinder, the same as the main ports C C, so that steam is simultaneously supplied thereto both by the main ports C and the auxiliary ports E E, and in like manner exhausted into the exhaust-port D. This I accomplish by placing upon the bottom of the steam-chest a reliefplate G, which is also provided with ports II H, corresponding to the main portsC C in the valve-seat with au exhaust-cavity K, corresponding with the exhaust-port D and with passages I I I I, which coincide with the auxiliary ports E E E E in the bottom of the steamchest, and passages J, chambered out in the relief-plate G, connecting the ports I-I therein with the passages I I in each end thereof, (these passages being shown in Fig. 3 and also by dotted lines in Fig. 5.) The under side of this relief-plate G is also provided with alongitudinal recess L of sufficient width and depth to receive a plate M, havinga central exhaust-recess N therein, which plate M is connected to and operated by the valvestem O of the engine and constitutes the valve. This recess L may, however, be made partially or wholly in the bottom of the steamchest instead of entirely in the relief-plate, if desired. I secure this relief-plate from lateral and longitudinal motion preferably by means of stud-pins a a', passing through holes b b in the relief-plate G and into the bottom ot' the steam-chest B, so that the relief-plate G can move up and down freely thereon.

Between the steam-chest cover P and the top of the relief-plate G, I preferably place springs f f to retain the relief-plate against the bottom of the steam-chest when there is no steam-pressure thereon.

In operation the steam enters the cylinder in two ways, one passage being downward directly under the end of the valve M through the main port C, and the other upward over the end of the valve M into the port H in the relief-plate G, and thence through the passages .I and down through the passages I I therein to and through the auxiliary ports E E in the bottom of the steam-chest, the exhaust-steam also passing out in like manner through the main ports and the auxiliary ports and passages communicated therewith, and by introducing the steam into the cylinder and discharging it therefrom in this manner I am enabled to largely reduce the length of the main ports C C and secu re a valve of about one-half the width necessary when the steam is introduced and discharged through the main ports alone, as in the usual construction of the steam ports and valves of steamengines.

Having thus fully described my invention,

IOO

ports in bottom of the steam-chest, and a slideer valve operating to simultaneously open Vand close the main ports in the bottom of steamchest andYY also the ports in the relief-plate, substantially as and for the purpose set forth.

2. The combination, in a balanced slidevalvemechanism,oflnainports,auxiliary ports atthe ends thereof, and aoentral exhaust-port in the bottom of the steam-chest, and a reliefplate covering said main and auxiliary ports, having ports therein corresponding to the main ports in the steam-chest and passages therefrom to the auxiliary ports in the steamohest, with a slide-valve having a central exhaust-opening therein and operating in a longitudinal groove between the relief-plate and the bottom of the steam-chest to simultaneously open and close the ports in the reliefplate and the main ports in the'hottom of the steam-chest, and springs on the top of the relief-plate, substantially as Yand for the purpose set forth.

In testimony whereof I affix my signaturein presence of two witnesses. 'Y

EDWARD L. MILLS.

Witnesses: Y

WM. P. HAYES, F. EINFELDT. 

